The present disclosure relates generally to capacitor structures, and more particularly, to multilayer ceramic capacitors having reduced acoustic noise.
This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
Many electronic devices include electronic circuits that employ capacitors for filtering, impedance matching, energy storage, and other applications. Ceramic capacitors have often been used in these electrical devices, in applications where the dimensions of the circuit boards in the device may be reduced. Due to the plasticity of the material and the high permittivity of the dielectric, ceramic capacitors may be produced in very compact and customized dimensions and shapes. For example, multilayer ceramic capacitors, e.g., ceramic capacitors having multiple electrodes forming a capacitor, may be used to obtain high capacitances in a compact package.
The materials forming the dielectric in multilayer ceramic capacitors may have a piezo-electric nature, i.e., changes in applied voltage may result in changes to the physical dimension of the capacitor. As a result, capacitors in high frequency circuits may present vibration, which may lead to generation of noise. The level of noise may be related to the frequency and voltage bias of the signal, as well as to the dielectric constant of the ceramic material. The noise may be further amplified by transmission to the circuit board that is coupled to the capacitor. While reduction of the noise may be achieved with reduction of the dielectric constant of the ceramic material, such reduction may lead to lower capacitance value and/or larger capacitor size.